This disambiguation page lists articles associated with the title UPD. If an internal link led you here, you may wish to change the link to point directly to the intended article.
Chronic smokers often have difficulty breathing because they develop Chronic Obstructive Pulmonary Disorder, or COPD. The two diseases that fall under that category are emphys â¦ ema and chronic bronchitis.
COPD can cause coughing that produces large amounts of mucus (a slimy substance), wheezing, shortness of breath, chest tightness, and other symptoms. Cigarette smoking is the leading cause of COPD. Most people who have COPD smoke or used to smoke. Long-term exposure to other lung irritantsâsuch as air pollution, chemical fumes, or dustâalso may contribute to COPD.